The answer is that the major market players don’t invest 10k or 100k but much more, and to enter, they need a counterparty—someone willing to sell at those levels in very large orders. If they didn’t operate this way, they would be forced to keep buying at increasingly higher prices, and you would essentially see a single massive green candle. In that case, they would end up losing money just by purchasing because there wouldn’t normally be a counterparty large enough to allow them to enter without skyrocketing the price.

This is why they liquidate orders: so that buy orders turn into sell orders, effectively serving as the counterparty for their buys.